Exciter lamp



May 30, 1939.

L. A. HERZIG EXCITER LAMP Filed June 17, 1937 INVENTOR' 6 5 N W. z m M 5% Patented May-30,1939

UNITED STATES EXCITER LAMP Leonard A Herzig, Brooklyn, N. Y., assignor to Clarence H. Venner, New York, N. Y.

Application June 17, 1937, Serial No. 148,635

2 Claims.

This invention relates to an exciter lamp for use in recording sound on or reproducing sound from a photographic sound record and particularly to an exciter lamp for use with a photographic sound record film containing a plurality of spaced parallel sound. record tracks.-

An object of the invention is to provide an exciter lamp which is capable of projecting a scanning beam of uniform intensity across the 0 entire active area of a film of the abovetype so that the scanning ray can be shifted from one sound .record track to another without physically moving the exciter lamp. Another object of the invention is to provide an exciter lamp of the above type which is simple and sturdy inconstruction and is provided with means to prevent displacement of the filament due to expansion or contraction thereof.

Another object of the invention is to provide a system for scanning a sound record film having a plurality of parallel sound record tracks with-.- out-physically shifting either the exciter lamp or the film. 7 Although the novelfeatures which are believed to be characteristic of this invention are set forth in the appended claims, the invention will be better understood by referring to the following description taken in connection with the accompanying drawing forming a part thereof, in which a specific embodiment has been set forth for purposes of illustration, and in which:

Fig. 1 is a broken side elevation of an exciter lamp embodying the invention;

Fig. 2 is a view showing a detail of the lamp;

and Hg. 3 is a diagrammatic view showing the invention embodied in a system for reproducing sound from a photographic sound record film.

The invention is particularly applicable to an exciter lamp for use with a photographic film having a plurality of spaced parallel sound record tracks thereon occupying, for example, a total width of approximately 1" which may be equivalent to the width of the film between sprocket 4 holes. The lamp is particularly constructed to project a scanning beam of uniform intensity across the entire active area of a film of the above type. For this purpose the lamp, as shown in Figs. 1 0 and 2, comprises an elongated filament I. This filament may, for example, be in the form of a round wire having a diameter of about .007" which is uniform throughout its' entire length. The upper end of the filament l is carried by 55' a supporting and connector bracket 2 which is mounted on a glass or other insulating press 3 attached to a base 4 which is adapted'to be in-' sorted in a standard socket. The bracket 2 is provided at its upper end with a horizontal extension 5 to which the filament l is attached. The lower end of the filament l is anchored in a socket 6 secured to a spring I which is mounted on a connector bracket 8 carried by the press 3. The spring I is adapted to hold the filament l under tension and to compensate for any changes 10 in length thereof due to expansion .or contraction. The bracket 2 is likewise resilient and assists in holding the filament under tension. In order to properly position the upper end of the filament a cross bracket i0 is provided-which comprises a wire attached to the top of the bracket- 2 and bent over at its ends to engage the inside-of the glass envelope H which surrounds the elements of the lamp.

The lamp is intended to be used ina vertical 20 position so that no sag will occur in the filament at the time that the filament becomes heated. in a lamp adapted to be used with a film having a width of about 1 as above mentioned, the filament may be approximately 1 in length 25 between supports so that the extreme ends of the filament are not utilized for the scanning beam. This is preferable because the supports tend to cool the'ends of the filament somewhat, so that the corresponding portions of the filament 3 may be at a lower intensity than the intermediate portions. By thus limiting the usable area of the filament to. the central portion thereof, and correspondingly increasing the length of the filament as required, a uniform scanning beam 35 may be obtained.

My improved lamp may be used in the system illustrated diagrammatically in Fig. 3 in which the light from the exciter lamp is focussed by a suitable cylindrical lens assembly i5 in the form of a narrow beam of uniform intensity across the entire active area of a photographic film 56 carrying a plurality of spaced sound record tracks.

, An, aperture plate ill, provided with an aperture derstood, however, that the photoelectric cell This photoelectric b 20 may be connected to control any desired audio frequency circuit.

In the operation of this system the exciter lamp is preferably mounted with the filament l extending vertically andfwith the light therefrom focussed in a narrow vertical beam across a hori zontal moving film. The aperture plate I! is shifted vertically to select the desired'sound record track which is scanned to produce a modulated light ray-which actuates the photoelectric cell 20 in the usual manner. At the end of each record track the apertureplate I! is-shifted to cooperate with the next record track. In this way the-scanning ray is shifted as desired without moving either the exciter lamp or the film.

It is to be understood that the lens assembly l5 may be designed to move with the aperture plate if desired although the lamp itself will remain stationary By mounting the filament in a vertical position and holding the same under tension, any changes in position due to expansion ,or contraction are eliminated and the accurate positioning and focussing thereof is facilitated. The life of the filament is increased by the elimination of the shocks and jars incident to shifting the lamp for scanning successive sound record tracks. Irregularities in light intensity due to vibration of the elements are also avoided.

36 Specific dimensions have been referred to above by way of example only. It is to be understood that the size of the various elements will depend upon the particular film with which the lamp is to operate. Although a specific embodiment has been shown and described, the invention is capable 0! various uses, and variouschanges and modifications may be made therein as will be apparent to a person skilled in the art. The scope of the invention is to be limited only in accordance with the following claims when interpreted in view of theprior art.

The invention claimed is:

1. An exciter lamp comprising a single elon gated filament, a bme carrying an insulating support and an envelope carried thereby, a bracket carried by said support and extending into supporting engagement withthe upper end of said filament, a second bracket carried by said support, a spring attached to the lower end of said filament and engaging said second bracket to hold said filament under. tension. and a wire car-' ried' by said first-mentioned bracket having and portions engaging the inside of said envelope to hold said filament in fixed position with respect to said envelope.

2. An exciter lamp comprising a base, an insulating support and an envelope carried thereby, a single elongated filament extending axially of said envelope, a bracket mounted on said support and extending into supporting engagement with the top of said filament, spacing means carried at the top of said bracket and engaging the inside of said envelope to hold the bracket in fixed position with respect thereto, a second bracket 

